December 22, 2014
Backed by stunning illustrations, David Christian narrates a complete history of the universe, from the Big Bang to the Internet, in a riveting 18 minutes. This is “Big History”: an enlightening, wide-angle look at complexity, life and humanity, set against our slim share of the cosmic timeline.
December 21, 2014
We hear plenty about the remaining radioactivity near the failed Chernobyl nuclear plant in Ukraine, but what about other places? Dereck Muller of Veritasium takes us on a tour of other historically radioactive sites such as Fukushima, Hiroshima, Marie Curie’s office, the Trinity test site, a uranium mine, and the basement of Pripyat’s hospital. The amount of radiation is presented in bananas as a visualization device to keep track of which place is more dangerous.
Cool chart here too.
December 2, 2014
There are three primary sources of smells that commonly occur after rain.
The first, the “clean” smell, in particular after a heavy thunderstorm, is caused by ozone. Ozone (scientifically known as trioxygen due to the fact that it is comprised of three oxygen atoms) is notably pungent and has a very sharp smell that is often described as similar to that of chlorine.
Another generally pleasant smell caused by rain is the deep, earthy smell, which is strongest after a dry spell or particularly heavy rainfall. This smell is the result of a bacteria commonly found in the soil.
Certain microbes, particularly streptomyces, produce spores during overly dry periods. The longer the soil goes without rain, the more spores that are usually present. The smell isn’t actually caused by the spores themselves, though. Rather it’s caused by a chemical excreted during the production of the spores known as “geosmin.”
The third cause of after-rain-smell is largely due to oils secreted by various plants. These oils collect in the environment and, when it rains, certain chemicals that make up the oils get released into the atmosphere (usually along with geosmin) causing a familiar and inviting scent. Learn more here.
December 2, 2014
Thousand of years ago most people were ‘employed’ in the field of agriculture.
Then a few hundred years ago when the Industrial Revolution occurred there was a gradual shift to manufacturing as a key employer.
Of course as time has marched on we have seen the number of jobs in both agriculture and manufacturing plummet as machinery and automation has taken jobs away from humans.
The constant push for increased efficiency and cost effectiveness will only see this trend continue:
– The transport industry will change it when self-driving cars and trucks become mainstream.
– Retail is already seeing changes to employment with the increase in self-checkout shops.
– Tireless robots will supplant humans from jobs such as cleaners, painters, and many more.
– Computers are already writing news articles.
It may not happen tomorrow, but it will come.
As an educator this brings up two key questions:
1) How do we ensure we are preparing our students for the only jobs that will be left in the creative, managerial and often university degree based fields?
2) Will we as teachers ever be superseded? People have talked about revolutionising education for a long time and will continue to do so. But will it happen ….
November 28, 2014
Layers of carbon one-atom thick can absorb blows that would punch through steel. Recent tests suggest that pure graphene performs twice as well as the fabric currently used in bulletproof vests, making it an ideal armour for soldiers and police.
Graphene is a sheet of single carbon atoms bonded together in a honeycomb shape. Because it is an excellent conductor of heat and electricity, graphene is already used in computers and electronics. But it’s also incredibly strong for its slight weight, potentially making it an ideal material for body armour.
Scientists found that graph performs twice as well as Kevlar and withstands 10 times the kinetic energy that steel can. Learn more here.
November 21, 2014
Cancer usually begins with one tumor in a specific area of the body. But if the tumor is not removed, cancer has the ability to spread to nearby organs as well as places far away from the origin, like the brain. How does cancer move to these new areas and why are some organs more likely to get infected than others?
November 13, 2014
The European Space Agency’s (ESA) Rosetta has become immortalised in space history as the first mission to land a spacecraft on a comet.
The ESA’s Rosetta mission sent a washing-machine-size probe named Philae to the surface of comet 67P/Churyumov-Gerasimenko.
Despite a thruster failure on Wednesday, the three-legged, 100-kilogram probe set down successfully using harpoons and ice screws to anchor itself to the rubber-duck-shaped comet, to begin what could be up to a year or more of intensive scrutiny of the comet’s composition and structure.
The landing was predicted to be particularly fraught because of the comet’s rough surface, which is covered with boulders, crevasses and craters. Against all the odds, the 100-kilogram lander arrived safely within its target site.
Rosetta was launched on 2 March 2004 and travelled 6.4 billion kilometres through the solar system before arriving at the comet in August.
During its decade-long journey, Rosetta has continued to push the boundaries of space engineering, from its three slingshot flybys of Earth and its two and a half year hibernation to Philae’s completely automated descent and landing.
Learn more here, here, here, here, here, here, here or here.
November 2, 2014
As it soared past Saturn’s large moon Titan recently, NASA’s Cassini spacecraft caught a glimpse of bright sunlight reflecting off hydrocarbon seas.
In the past, Cassini had captured, separately, views of the polar seas and the sun glinting off them, but this is the first time both have been seen together in the same view. Check it out …
October 19, 2014
The brain uses a quarter of the body’s entire energy supply, yet only accounts for about two percent of the body’s mass. So how does this unique organ receive nutrients and, perhaps more importantly, rid itself of wastes? New research suggests it has to do with sleep.
Back in 1942, we averaged almost 8 hours of sleep a night — now that’s down to 6.8. (Seven to 9 hours per night are what’s generally recommended.) For a list of 25 more unfortunate risks of partial and total sleep deprivation go here.
October 5, 2014
Scientists have photographed the largest gathering of Pacific walruses ever recorded, on a beach in northern Alaska.
It’s hardly the first big walrus gathering to be documented. But scientists say the size of the gatherings are growing as climate change melts Arctic sea ice, depriving walruses of their sunning platforms of choice.
As the ocean heats up due to global warming, Arctic sea ice has been locked in a downward spiral. Since the late 1970s, the ice has retreated by 12 percent per decade. Learn more here.